In a known manner, axleboxes are mounted on railway vehicles such as trains, in particular on passenger coaches and freight cars. Generally, a railway vehicle includes several bogies. Each bogie comprises a frame, two wheelset and four axleboxes. Each wheelset comprises an axle supporting two wheels. The axlebox is the linking element between the rotating wheelset and the quasi-static frame of the bogie. The axlebox comprises a housing receiving a bearing unit. The housing is mounted for the lifetime of the bogie, by example thirty years, while the bearing is dismounted from the wheelset on a regular basis, for example every one million kilometers or every one or two years.
To facilitate maintenance operations, it is known to provide the axlebox with a split housing in two parts, by example an upper arm and a lower arm, or in three parts including a sleeve protecting the bearing unit. The split housing enables an easy radial dismounting of the wheelset, with the bearing and the axle which remain assembled.
U.S. Pat. No. 2,811,396 discloses two embodiments of an axlebox, having a generally rectangular cross section. In the embodiment of FIGS. 6 to 8, the axlebox comprises an upper casing part, a bottom casing part formed by a removable plate, a bearing receiving the axle of a wheelset, a rectangular sleeve protecting the bearing unit, and a resilient material disposed between the sleeve and the upper casing part.